Managing Extensions 53
virtual devices such as the pcXset™ PC soft telephone Client and the
ConneXtions H.323 Gateway.
The extension length (either 3 or 4), which applies to all extensions on a
system, indicates that all extensions contain that number of digits. You
cannot mix 3-digit and 4-digit extensions within the same NBX system.
The NBX 100 and the SuperStack 3 NBX systems both support 3-digit and
4-digit dial plans, although there are some differences in the extension
ranges as noted in these tables. By default, the NBX 100 uses a 3-digit
dial plan, and the SuperStack 3 NBX uses a 4-digit dial plan.
Tab le 8 lists typical extension ranges in a 3-digit and a 4-digit dial plan.
Tab le 9 describes these ranges in more detail and gives the default ranges
and values for 3-digit and 4-digit dial plans.
Tab le 8 Typical Extension Ranges for 3-digit and 4-digit Dial Plans
Extension Type 3-digit 4-digit
Telephones NBX 100:
100–449 SuperStack 3 NBX:
1000–3999
Auto Attendant 500–599 500, 501, plus 5500–5599
Hunt Group NBX 100:
450–499 SuperStack 3 NBX:
4000–4099
External Extensions
(includes line card
ports and Call Park)
600–799
(external Auto Discovery
starts at 750)
6000–7999
(external Auto Discovery
starts at 7250)
Call Park (must fall
within External
Extension range)
NBX 100:
601–609 SuperStack 3 NBX:
6000–6099
Note 1: The NBX 100 is shipped with a factory default 3-digit dial plan. If you import
any 4-digit plan, you must manually specify any 4-digit extension ranges that are not
set by the imported plan. You must also manually change any device extensions so
that they fall within the appropriate range.
Note 2: The Superstack 3 NBX is shipped with a 4-digit dial plan. If you import any
3-digit plan, you must manually specify any 3-digit extension ranges that are not set
by the imported plan. You must also manually change any device extensions so that
they fall within the appropriate range.
Note 3: TAPI Route Point extensions occur in the same range as telephones. TAPI
Route Point extensions do not appear in telephone lists within the NBX NetSet utility.
For more information about TAPI Route Points, see TAPI Route Points on page263.